Materials Literature
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Thermogravimetric analysis (TGA) has demonstrated that multiwalled nanotubes (MWNTs) annealed at 2200 to 2800 °C are more air stable than as-produced MWNTs, diamond, graphite, and annealed diamond. The annealed MWNTs are similar in stability to annealed graphite. Defect sites along the walls and at the ends of the raw…
Progress reports are a new type of article in Advanced Materials, dealing with the hottest current topics, and providing readers with a critically selected overview of important progress in these fields. It is not intended that the articles be comprehensive, but rather insightful, selective, critical, opinionated, and…
A green chemistry approach to nanoparticle synthesis is the exciting possibility opened up by the fungus Fusarium oxysporum. The fungus (shown in the flask on the left), when exposed to aqueous AuCl4− ions, reduces the metal ions; this leads to the extracellular formation of gold nanoparticles (shown in the flask on t…
In the processes that are used to produce single-walled nanotubes (electric arc, laser ablation, and chemical vapor deposition), the typical lengths of tangled nanotube bundles reach several tens of micrometers. We report that long nanotube strands, up to several centimeters in length, consisting of aligned single-wal…
A novel compound Nd 3 Fe 26.5 Re 2.5 was synthesized. The structure and magnetic properties of the compound were investigated by means of x-ray powder diffraction (XRD) analysis and magnetic measurements. Nd 3 Fe 26.5 Re 2.5 crystallizes in a monoclinic Nd 3 (Fe, Ti) 29 structure with space group A 2/ m . The lattice…
The crystal structure and electronic properties of δ-phase bronze Tl x V 2 O 5 , where 0.47⩽ x ⩽0.496, have been explored by means of x-ray four-circle diffraction and through measurements of lattice constants, electrical resistivity, thermoelectric power, magnetization, and electron paramagnetic resonance. The struct…
An effective thermal conductivity in layer melt crystallization was explored based on a model considering inclusions inside a crystalline layer during crystal growth, molecular diffusion of inclusions migration due to temperature gradient and heat generation due to recrystallization of inclusions in the crystalline la…
The phase transformation and magnetic properties of nanocomposite Nd 2 Fe 14 B/α-Fe magnets with W and Co additions, according to the composition formula (1- x wt%- y wt%) Nd 8.6 Fe 85 B 6.4 + x wt% W{} + {} y wt% Co, prepared by mechanical alloying, have been systematically studied. It has been observed that separati…
Abstract The conformational characteristics, as embodied in the unperturbed mean‐square end‐to‐end distances (〈 r 2 〉 o ) and the characteristic ratios of the dimensions [ C n = 〈 r 2 〉 o /( n 〈 l 2 〉] are calculated for the para, meta, and ortho isomers of poly(ethylene phthalate)s: poly(ethylene terephthalate) (PET)…
An extensive extended x-ray absorption fine-structure (EXAFS) study at the Mn K edge of the La 1- x Ca x MnO 3 and Tb 1- x Ca x MnO 3 ( x ⩾0.5) series, as a function of temperature up to values around 600 K, has been performed. An accurate multiple-scattering analysis has been carried out; it shows that the paramagnet…
We present three-dimensional simulations of field emission through an oscillating barrier from ideally open (10,0) and (5,5) carbon nanotubes without adsorption, by using a transfer-matrix methodology. By introducing pseudopotentials for the representation of carbon atoms and by repeating periodically a basic unit of…
Nanometre-sized domains of block copolymers can be utilized as so-called nanoreactors to synthesize a variety of nanoparticles. In this nanoreactor scheme, the domain size and period of block copolymers should be expanded to incorporate nanoparticles. We investigated changes in the domain period by gold nanoparticles,…
Al 2 O 3 −SiO 2 glasses were prepared for doping with Sm 3+ ions using a sol−gel method, followed by X-ray irradiation, in which formation of the Sm 2+ ions and persistent spectral hole burning (PSHB) were investigated. The X-ray irradiation brought about hole centers in the oxygen ions bound with Al 3+ ions. And the…
Abstract The residual entropy of amorphous polyethylene (PE) at 0 K is discussed within the framework of the heat capacity ( C p ). The measured C p of the liquid was extended from the glass transition to low temperature by separately finding its three parts—the vibrational, conformational, and external contributions—…
High resolution electron energy loss spectroscopy (EELS) measurements of the insulating, layered cuprate compound ${\mathrm{Sr}}_{2}{\mathrm{CuO}}_{2}{\mathrm{Cl}}_{2}$ have been performed with a transferred momentum near $\mathbf{k}=0$ and in a wide energy range up to 20 eV. To interpret the data a semiquantitative e…
Soft x-ray magnetic circular dichroism (XMCD) spectra have been investigated for different crystallographic projections of CrO2. Strong anisotropic orbital Cr 3d contributions and a change of sign of the XMCD signal is observed and attributed to t(2g) majority states near the Fermi level. Additionally, moment analysis…
We present Monte Carlo simulations in the NVT ensemble for spherical particles of diameter σ interacting via a hard-core potential with a square-shoulder (SS) repulsive barrier, a square-well (SW) attraction, and a second SS repulsion. This discrete potential is used to mimic the pair interaction in confined colloidal…
The ac electrical properties of acetylene black composites mixed into ethylene butylacrylate copolymer (EBA) and into poly (methyl methacrylate) (PMMA) have been measured in thermal cycling and isothermal annealing experiments. The results show that changes in electrical properties are due to rearrangement of gaps bet…
Combined analyses using NMR, EPR and Mössbauer spectroscopy as well as SQUID magnetometry have revealed that highly saddle shaped Fe(OETPP)I adopts an essentially pure intermediate spin state in spite of the coordination of an iodide ligand.
We examine the effect of pressure on the smectic-A-isotropic phase transition within the Landau phenomenological theory. The influence of pressure on the smectic-A-isotropic phase transition is discussed by varying the coupling between the orientational and the translational order parameter. The transition is found to…